The hurricane evacuation model’s influence on development

CAN KEYS DEVELOPMENTS REALLY STOP IN 2023

How we got to this point - A drawing of a face - Zi wei dou shu

#1 How we got to this point (Sept. 27, 2018)
#2 The hurricane evacuation model’s influence on development (Oct. 4, 2018)
#3 What the “takings” lawsuit might look like (Oct. 11, 2018)
#4 Options to detour chaos (Oct. 18, 2018)
#5 In conclusion … (Oct. 25, 2018)

In a little more than five years, new development will come to a grinding halt in the Florida Keys. At least, that is what the State of Florida has decreed for the islands it has designated an “Area of Critical Concern.” Beginning in 2023, it will no longer issue NEW building permits for Keys municipalities. None. Zilch. Zip. Nada. If this comes to pass, what happens next? Will landowners sue because the state (and local governments) is gutting the value of their investment by preventing them from building their dream home on their vacant lot? Will that raise taxes? What will happen to real estate values? Will builders be out of business? The ramifications are wide and far-reaching. The future starts now.

By Frank Greenman & Sara Matthis

Florida’s Comprehensive Planning law requires local government to inventory and evaluate all parts of a community to be able to determine future needs for development. This includes potential population growth, land area, water supply and utility services, school capacity, environmental concerns, and economic sustainability, among much else. The idea is to plan development rationally to maximize success to build better communities, and the services needed to supply them. The planning process is not to inhibit growth, but to accommodate it wisely.

But in the Florida Keys, there is another hurdle to development that has created a brick wall that will stop all development, irrespective of what other data might exist to encourage it. Development in the Keys stops when the state determines that we cannot evacuate all – 100 percent – of our population in 24 hours, in the face of a hurricane. There are many ways government can stop development – setbacks, environmental constraints, zoning restrictions – but it’s rare if not unprecedented that any jurisdiction would stop all development on the threat of a natural disaster. After all, Europeans have lived in the Keys for more than 300 years, and have certainly suffered damage from hurricanes, but nobody has asserted that they couldn’t live here because of the threat of a storm. Nor, to the best of legal experts’ knowledge, has any government, anywhere, taken that position.

But Florida has said that to the people of the Florida Keys. The state has determined that the 24-hour evacuation requirement will be impossible to meet after 2023, and there will be no more new building permits issued in the Florida Keys after that date.

Florida’s no-permit edict is based on a “Regional Evacuation Transportation Analysis” prepared by the South Florida Regional Planning Council that forecasts the hurricane evacuation that will occur in South Florida. The study is based on limited assumptions. For example, it has devoted a very limited amount of consideration to behavioral elements. That part is based on a 2008 statewide regional evacuation study program that asked four questions — how many people would evacuate, when would they leave, what type of refuge would they seek, where they would travel for refuge. In Monroe County, the survey consisted of 400 random telephone interviews. 

“The study is all about modeling. And a big part of modeling has to deal with behaviors which are not as quantifiable,” said Monroe County Emergency Management Director Marty Senterfitt. “The evacuation model is a process that falls under growth management and has its own set of state statutes that govern it. The practice side is my world of emergency management. It is a totally different part of government. You may have growth management policy, but you have the practitioners like me who carry out the hurricane evacuation.”

First and foremost, Monroe County’s growth rate is based on the study’s assumption of a 100 percent evacuation, when anyone who lives in the Keys knows you couldn’t get 100 percent of the Keys population to accept a $20 bill, much less unanimous evacuation. And why just 24 hours, in light of improved meteorological predictions, and the reality that evacuation begins much earlier in the Florida Keys?

“Our higher education institutions — University of Florida, Florida State University — have been studying hurricane evacuation for many years, trying to find a better model,” Senterfitt said. “But, because you’re dealing with social behaviors, that’s where the challenges are. Models are cutting edge for what they are, but hurricanes are all so different. When you start building behavioral models based on the last storm, the whole model goes out the window.”

The Regional Evacuation Transportation Analysis is limited in other areas as well. It evaluates evacuation in Dade and Broward Counties by anticipated storm surge and wind strength, based on anticipated landfall. In the Keys the evacuation is “not based on storm surge, but apportioned geographically, by sub regions: Key West, Lower Keys, Middle Keys and Upper Keys.” The growth management policy tasks the Keys with a total evacuation without determining the effect or strength of a landfall anywhere along the 130-mile length of the Keys.

The analysis apportions greater clearance times for the Upper Keys than the Lower Keys, despite the obvious fact that evacuation times would be shorter in the Upper Keys than in Key West and the Lower Keys. For Key West the clearance time is 16.5 hours; for the Upper Keys, 32.5 hours — it is unclear what those numbers are based on. What’s the logic for the longer evacuation time for the Upper Keys? The study only states that the “clearance time” is calculated from the point an evacuation order is given, to the point in time when the last vehicle exits the county. And, the study posits that the Keys will evacuate 24 hours before Dade and Broward, irrespective of the Hurricane’s strength and location, and then adds Monroe County into the traffic congestion caused by the Dade-Broward populations. It does not consider evacuation to the west, Collier County and west Florida, instead of north into Dade. 

The Regional Evacuation Transportation Analysis relies on “maximum sustainable traffic flow rates” to show that the evacuation cannot happen in less than 24 hours, but it does not take into account the very efficient and experienced Monroe County Sheriff’s Office that successfully met that evacuation time frame for Hurricanes Wilma, Georges, and most significantly Irma. Nor did it consider the use of one way traffic on U.S. 1, which has not been necessary, but has been planned, nor the use of the newly constructed shoulders on the 18 mile stretch, although shoulder use is considered for I-95 and the Turnpike.

The analysis uses 100 percent occupancy for the time clearance model, including site built homes, mobile homes, and hotel/motels, for a total evacuation population of 89,351 (in 2015). It does not consider the practice of how Monroe County actually calls evacuations — in zones and phases. For example, the county can call for an evacuation of all motels and hotels and RV parks 72 hours before the storm. Also, the analysis does not consider that many of the Keys’ “site built homes” are for winter residents only, and are unoccupied during hurricane season. In other words, the study calculates Keys’ population very loosely, and requires total evacuation of that number within a very specific time.

Senterfitt said from a logistical standpoint, fewer people make for an easier evacuation but the equation is much more nuanced.

“Even when I’m speaking publicly, I try to detach growth management policy with hurricane evacuation decision making. They don’t deserve to be in the same conversation,” he said.

And, yet, the state will stop new development in the Keys in five years despite this disconnect.

— Frank Greenman is a retired general land use attorney living in the Florida Keys. He practiced for 38 years, as well as was one of the first councilmen elected to the City of Marathon, established in 1999. Sara Matthis is the editor of the Weekly Newspapers.

Please send your thoughts and comments about this issue to sara@keysweekly.com. Comments will be gathered and published, as space permits, with the author’s name and hometown. All of the articles will be available at keysweekly.com as they publish.

 

What is the ‘Miller Model?’

Miller Model is short speak for hurricane evacuation analysis. It was reportedly developed by a professor at the University of Miami for the Florida Keys, about 18 years ago, but despite weeks of searching, the Weekly Newspapers could not find a hard copy, and it’s only referenced online by other hurricane evacuation studies. 

We did, however, find this tidbit from the University of Utah, published in 2010 by Reid Ewing.

“The conventional model is widely referred to as the Miller Model. The model is a spreadsheet-based program executed in Microsoft Excel. The model is comprised of 39 Excel spreadsheets, 31 of which relate to individual roadway segments. The 31 roadway segments are defined by roadway cross-section, capacity, and mile markers. The model is deterministic, predicting evacuation movement link-by-link, in 2-minute increments, assuming a 30 mph average driving speed.”

Sara Matthis
Sara Matthis thinks community journalism is important, but not serious; likes weird and wonderful children (she has two); and occasionally tortures herself with sprint-distance triathlons, but only if she has a good chance of beating her sister.